My bad. Yamaha normally begins production in September. My frame, in the 6900s, is labelled in 2/87. As to clutch lever pivots, '87-'89 used 8mm bolts, which tended to wear the lever pivot hole out. In 1990, they upgraded to 10mm bolts. The perches/levers from '90 onward retrofit, as do EX650 (Ninja 650) perches and levers - at least in the gen1 650s.
I finally figured out why I like Ducatis: With their exhaust note and dry clutch, they sound almost like a Guzzi!